Abstract: Based on orthogonal design, optimization design of rotational flow self-priming pump was done through large eddy model simulation (LES) by using CFD software, and the influence of pump body geometrical parameters on its performance was studied. Orthogonal scheme of four factors and three levels was designed, and the influence orders of geometrical parameters on head and efficiency at design point, head and efficiency at the best efficiency point, and maximum self-suction height were gotten by using range analysis of the calculated data. The optimal parameter combination was received by comprehensive balance analysis of the disposed data result. And performance test of optimal parameter combination was accomplished, and the reliability of theoretical calculation was proved. The calculation and analysis results were instructive to the optimization design of rotational flow self-priming pump.